Method of and apparatus for exhaust control and supplying tempered makeup air for a grease extraction ventilator

Abstract

A method of supplying tempered makeup air to a room in conjunction with a grease extraction ventilator disposed above cooking equipment in the room and having removal means for removing grease and smoke particles and the like from air mixed with products of cooking, which includes removing heated air and the remaining products of cooking, after passage through the removal means, through a discharge duct; tempering fresh air in a heat exchanger and discharging the tempered fresh air into the room; passing incoming air to the discharge duct in a manner which automatically regulates the amount of exhaust and makeup air required to remove and replace the minimal amount of outside air to eliminate heat, odors, smoke, gases, grease and dirt as the cooking load changes; and causing incoming air, which is not passed to the discharge duct, to become a portion of the tempered air for discharge into said room. The removal means may be water contact means and there may be heat exchange, at least indirectly, between water from the water contact means with at least a portion of the fresh air. Control of the passage of incoming air to the exhaust duct may be inversely in accordance with the temperature of the heated air and products of cooking, such as measured adjacent the entrance of the exhaust duct and/or the entrance of the grease extraction ventilator. The apparatus corresponds to the method, but may further include an inlet duct for fresh air and a bypass duct between a fresh air plenum chamber and the exhaust duct.

What is claimed is: 
     
       1. A method of supplying tempered makeup air to a room in conjunction with a grease extraction ventilator disposed above cooking equipment in said room and having removal means for removing grease and smoke particles and the like from air mixed with products of cooking, which comprises: causing heated air and products of cooking from said cooking equipment to pass through said removal means of said grease extraction ventilator;   removing said heated air and remaining products of cooking, after passage through said removal means, through a discharge duct;   conducting fresh air through an intake duct to heat exchange means for tempering the same;   discharging the tempered fresh air into said room;   establishing a source of incoming air;   passing incoming air to said discharge duct inversely in accordance with the temperature of said heated air and products of cooking; and   causing incoming air, which is not passed to said discharge duct, to become a portion of said tempered air for discharge into said room.   
     
     
       2. A method as defined in claim 1, including: controlling the passage of incoming air to said exhaust duct inversely in accordance with the temperature measured adjacent the entrance of said discharge duct.   
     
     
       3. A method as defined in claim 1, including: controlling the passage of incoming air to said discharge duct inversely in accordance with the temperature measured above said cooking equipment prior to engagement of said heated air and products of cooking with said removal means.   
     
     
       4. A method as defined in claim 2, including: measuring the temperature of said heated air and products of cooking adjacent the intake of said discharge duct; and   controlling the amount of incoming air supplied to said discharge duct generally inversely to the aforesaid temperature measurements but secondarily to temperature measurements above said cooking equipment prior to engagement of said heated air and products of cooking with said removal means.   
     
     
       5. A method as defined in claim 1, wherein: said removal means of said grease extraction ventilator comprises water contact means;   said incoming air supplied to said discharge duct comprises a portion of said fresh air; and   effecting, at least indirectly, an exchange of heat between water of said water contact means and at least a portion of such fresh air in said heat exchange means.   
     
     
       6. A method as defined in claim 5, including: removing moisture droplets from said heated air and products of cooking after passage through said water contact means but prior to the entrance of said discharge duct.   
     
     
       7. A method as defined in claim 6, including: controlling the passage of incoming air to said discharge duct inversely in accordance with the temperature between the area of removal of moisture droplets and the area adjacent the entrance of said discharge duct.   
     
     
       8. A method as defined in claim 5, including: passing said water from said water contact means in heat exchange relationship with a heat transfer medium; and   passing said heat transfer medium in heat exchange relationship with at least a portion of said fresh air for tempering the same.   
     
     
       9. A method as defined in claim 8, wherein: said heat transfer medium contains an anti-freeze.   
     
     
       10. A method as defined in claim 8, including: adding heated water to said water from said water contact means prior to heat exchange with said heat transfer medium to supplement the heat supplied by said water from said water contact means when the temperature of said fresh air is sufficiently below the temperature in said room that the amount of heat supplied through said water from said water contact means is insufficient to heat the heat transfer medium to a desired temperature.   
     
     
       11. A method as defined in claim 8, including: adding cooled water to said water from said water contact means, prior to heat exchange with said heat transfer medium to supplement the cooling supplied by said water from said water contact means, when the temperature of said air is sufficiently above the temperature of said room that the amount of cooling supplied through said water contact means is insufficient to cool the heat transfer medium to a desired temperature.   
     
     
       12. Apparatus for supplying tempered makeup air to a room in conjunction with a grease extraction ventilator disposed above cooking equipment in said room and having removal means for removing grease and smoke particles and the like from air mixed with products of cooking, which comprises: a discharge duct having suction means for causing heated air and products of cooking to pass through said removal means of said grease extraction ventilator and for removing said heated air and remaining products of cooking, after passage through said removal means;   an intake duct having blower means for producing a flow of fresh air;   means for tempering at least a portion of such fresh air;   means for directing tempered fresh air into said room;   a bypass duct extending to said discharge duct;   means for supplying incoming air to said bypass duct;   means for controlling the flow of air through said bypass duct to said discharge duct;   means responsive to the temperature of said heated air and products of cooking for controlling the flow of air through said bypass duct to said discharge duct, inversely in accordance with such temperature; and   means for causing incoming air which is not supplied to said discharge duct to become a portion of said tempered air.   
     
     
       13. Apparatus as defined in claim 12, wherein: said temperature responsive means is responsive to the temperature adjacent the entrance of said discharge duct.   
     
     
       14. Apparatus as defined in claim 12, wherein: said temperature responsive means is responsive to the temperature of said heated air and products of cooking prior to engagement thereof with said removal means.   
     
     
       15. Apparatus as defined in claim 12, including: means for controlling the flow of air through said bypass duct primarily responsive to the temperature adjacent the entrance of said discharge duct and secondarily responsive to the temperature of said heated air and products of cooking prior to engagement thereof with said removal means.   
     
     
       16. Apparatus as defined in claim 12, wherein: a damper in said bypass duct is moved to control the flow of air therethrough.   
     
     
       17. Apparatus as defined in claim 12, wherein: said removal means comprises water contact means;   said incoming air supplied to said bypass duct comprises a portion of said fresh air; and   means for effecting, at least indirectly, an exchange of heat between water of said water contact means and at least a portion of such fresh air.   
     
     
       18. Apparatus as defined in claim 17, including: means for removing droplets of moisture from said heated air and products of cooking, after passage thereof through said water contact means but before passage thereof into said exhaust duct.   
     
     
       19. Apparatus as defined in claim 17, including: first heat exchange means for effecting heat exchange between said water from said water contact means and a heat exchange medium;   second heat exchange means for effecting an exchange of heat between said heat exchange medium and said fresh air; and   means for circulating said heat exchange medium between said first heat exchange means and said second heat exchange means.   
     
     
       20. Apparatus as defined in claim 19, wherein: said heat transfer medium is liquid and contains an anti-freeze.   
     
     
       21. Apparatus as defined in claim 19, including: a connection for adding supplemental water to said water from said water contact means between said water contact means and said first heat exchange means;   whereby heated water may be added to said water from said water contact means to supplement the heat supplied by said water from said water contact means, when the temperature of said fresh air is sufficiently below the temperature in said room that the amount of heat supplied through said water from said water contact means is insufficient to heat the heat transfer medium to a desired temperature; and   whereby cooled water may be added to said water from said water contact means to supplement the cooling supplied by said water from said water contact means, when the temperature of said fresh air is sufficiently above the temperature in said room that the cooling supplied through said water from said water contact means is insufficient to cool the heat transfer medium to a desired temperature.   
     
     
       22. Apparatus as defined in claim 19, including: means providing a water bath in said grease extraction ventilator and means for causing said heated air and products of cooking to engage said water bath;   baffle means above said water bath around which said heated gases and cooking products flow after engaging said water bath;   means for spraying returned water from said water bath into said ventilator adjacent said baffle means; and   means for supplying said spraying means with said water after flow through said second heat exchange means.   
     
     
       23. A method of supplying tempered makeup air to a room in conjunction with a grease extraction ventilator disposed above cooking equipment in said room and having removal means for removing grease and smoke particles and the like from air mixed with products of cooking, which comprises: causing heated air and products of cooking from said cooking equipment to pass through said removal means of said grease extraction ventilator;   removing said heated air and remaining products of cooking, after passage through said removal means, through a discharge duct;   conducting fresh air through heat exchange means for tempering the same;   discharging the tempered fresh air into said room;   establishing a source of incoming air;   passing incoming air to said discharge duct in a manner which automatically regulates the amount of exhaust and makeup air required to remove and replace the minimum amount of outside air to eliminate heat, odors, smoke, gases, grease and dirt as the cooking load changes; and   causing incoming air, which is not passed to said discharge duct, to become a portion of said tempered air for discharge into said room.   
     
     
       24. Apparatus for supplying tempered makeup air to a room in conjunction with a grease extraction ventilator disposed above cooking equipment in said room and having removal means for removing grease and smoke particles and the like from air mixed with products of cooking, which comprises: a discharge duct having suction means for causing heated air and products of cooking to pass through said removal means of said grease extraction ventilator and for removing said heated air and remaining products of cooking, after passage through said removal means;   an intake duct having blower means for producing a flow of fresh air;   means for tempering at least a portion of such fresh air;   means for directing tempered fresh air into said room;   a bypass duct extending to said discharge duct;   means for supplying incoming air to said bypass duct;   means for controlling the flow of air through said bypass duct to said discharge duct;   means for controlling the flow of air through said bypass duct in a manner which automatically regulates the amount of exhaust and makeup air required to remove and replace the minimum amount of outside air to eliminate heat, odors, smoke, gases, grease and dirt as the cooking load changes; and   means for causing incoming air which is not supplied to said discharge duct to become a portion of said tempered air.